There have certainly been disappointments in vaccine technology recently -- like Sanofi's announcement that its vaccine against dengue fever was less effective than hoped in a clinical trial -- but researchers are also making great progress in other areas.

Here are six areas where vaccine innovation is especially active:

Women's cancers:Hundreds of vaccines to prevent or treat various forms of cancer are in development, but one segment that's attracted a lot of attention is women's cancers. Two preventative HPV vaccines are already on the market, so some companies like PDS Biotechnology and Inovio Pharmaceuticals are focusing instead on therapeutic vaccines for women with HPV. Ovarian cancer has been a tough area for researchers to crack, but Quest PharmaTech is currently recruiting for a phase II trial of its immunotherapy, and Heat Biologics also hopes to begin a trial of its vaccine in ovarian cancer late this year.

Hospital-acquired infections: Vaccines have become a huge target for institutions and companies looking toward the hospital-acquired infection market, starting with Big Pharma. Sanofi Pasteur has vaccines for C. difficile, Staph and Pseudomonas aeruginosa infections in its pipeline. GSK has several infectious-disease vaccines in its pipeline (PDF), as does Novartis. Merck halted a study of its MRSA vaccine last year, but University of Rochester researchers said early this year they've developed one. Vaccines for Staphylococcus aureus are also under development by the Florida company Nabi and North Dakota company NovaDigm Therapeutics.